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1.
Clin Otolaryngol ; 42(2): 234-238, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27383045

RESUMO

OBJECTIVES: This study is designed to determine the clinical predictors of malignancy in the atypia of undetermined significance (AUS) category resulted from thyroid fine needle aspiration (FNA). DESIGN: Retrospective cohort study. SETTING: Dong-A University Medical Center, Busan, Korea. PARTICIPANTS: Sixty-two patients who underwent thyroid surgery from January 2010 to December 2013, following a diagnosis of AUS from preoperative thyroid FNA. MAIN OUTCOME MEASURES: We investigated the age, gender, maximum size and site of the nodules, ultrasonographic findings, cytological features, BRAF gene mutation, surgical method, number of AUS on repeated FNA and final pathologic results. RESULTS: Forty-one of sixty-two patients underwent total thyroidectomy and the rest had lobectomy. The final pathologic results were 41 malignancies and 21 benign diseases. Nodules less than 1.5 cm, ultrasonographic findings suggestive of malignancy were risk factors for malignancy on univariated analysis (P < 0.001). Multivariated analysis showed that nodules less than 1.5 cm, ultrasonographic findings suggestive of malignancy and more than 2 results of atypia from repeated FNAs were significant risk factors for malignancy (P < 0.001). A BRAF gene mutation analysis was performed in 38 patients, and 13 patients had the mutation. All patients with the BRAF gene mutation had been diagnosed with papillary thyroid cancer (P > 0.05). CONCLUSIONS: We recommend close observation or diagnostic surgery in patients with nodules <1.5 cm and with two or more malignant ultrasound feature and a BRAF mutation, or with two or more AUS findings on repeated FNAs.


Assuntos
Biópsia por Agulha Fina , Neoplasias da Glândula Tireoide/patologia , Adulto , Idoso , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia , Estudos Retrospectivos , Fatores de Risco , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/métodos
2.
Clin Otolaryngol ; 42(6): 1167-1171, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28166397

RESUMO

OBJECTIVES: This study was designed to evaluate the usefulness of intra-operative frozen section for the evaluation of microscopic extrathyroidal extension (ETE) in papillary thyroid carcinoma (PTC). DESIGN: Retrospective cohort study. SETTING: Dong-A University Medical Center, Busan, Korea. PARTICIPANTS: Three hundred and sixty-four patients who underwent thyroid surgery from January 2000 to December 2010 with PTC confined to one unilateral lobe as diagnosed using preoperative ultrasonography were enrolled. MAIN OUTCOME MEASURES: The patients who had microscopic ETE on frozen section were classified into "group A," and those who did not have microscopic ETE on frozen section were classified into "group B." Clinicopathologic factors including age, gender, size of the tumour, extent of operation, ETE, multifocality, bilaterality, lymph node metastasis and recurrence were compared between the two groups. RESULTS: Of the 364 patients enrolled, ETE was confirmed in 100 patients (group A, 27.5%) on frozen biopsy. The nodule size in group A (0.94±0.87 cm) was larger than that in group B (0.86±0.79 cm) (P=.042). In group A, 15 patients (15%) showed multifocality and 11 patients (14.47%) showed bilaterality. In group B, 37 patients (14.02%) showed multifocality and seven patients (43.35%) showed bilaterality. They did not differ significantly between the two groups (P=.811, P=.182). There was a higher frequency of lymph node metastases in group A (52/86, 60.47%) than in group B (7/16, 43.75%, P=.214). Recurrence was observed in only two patients who had received thyroid lobectomy as the initial surgery in group A. CONCLUSIONS: Intra-operative frozen biopsy can be a useful method for identifying the microscopic ETE. During the surgery, it can also help the surgeon to decide the optimal extent of surgery and the need for central compartment neck dissection in PTC patients.


Assuntos
Carcinoma Papilar/patologia , Carcinoma Papilar/cirurgia , Secções Congeladas , Cuidados Intraoperatórios , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Seleção de Pacientes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Câncer Papilífero da Tireoide , Resultado do Tratamento
3.
J Nanosci Nanotechnol ; 14(7): 5473-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24758052

RESUMO

The photoluminescence properties and formation mechanism of a novel stoichiometric phosphor are presented. Nanoplates of pure single-phase crystalline Eu2O2CO3 oxycarbonate (hexagonal type-II) were synthesized by dry autoclaving under autogenic pressure (under 3 MPa) using an efficient, high yield solid state green-chemistry route that can be extended to other rare-earth oxycarbonate and oxide systems, resulting in the full conversion of a simple commercial precursor in single-crystalline nanoplates with strong visible luminescence. Phosphors made of an oxide host and an active luminescent dopant ion are the commercial standard (i.e., Y2O3:Eu). It is generally considered that the activity of luminescent species, such as Eu3+, is quenched and disappears above a certain concentration of them in the lattice (concentration quenching). The truly stoichoimetric oxycarbonate phosphor without active dopant ions exhibits very strong red emission when excited by different excitations, in the UV and visible range, without any concentration quenching effect. The bright red light emission spectra of the of the photo-excited phosphor nanoplates under UV and visible light excitation is compared with that of a standard Y2O3:Eu commercial red phosphor powder, and the thermal conversion mechanism is proposed to obtain the single-phase stable stoichiometric oxycarbonate nanoplates.

4.
Food Microbiol ; 41: 91-5, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24750817

RESUMO

Two molecular-based methods for estimating capsid integrity as a proxy for virus infectivity were used to produce thermal inactivation profiles of Snow Mountain virus (SMV), a prototype human norovirus (HuNoV). Monodispersed virus suspensions were exposed to 77, 80, 82 and 85 °C for various times, pre-treated with either propidium monoazide (PMA) or RNase, and subjected to RNA isolation followed by RT-qPCR amplification. D-values were 25.6 ± 2.8, 3.1 ± 0.1, 0.7 ± 0.04 and 0.2 ± 0.07 min at 77, 80, 82 and 85 °C, respectively for PMA-treated SMV; and 16.4 ± 0.4, 3.9 ± 0.2 0.9 ± 0.3 and 0.12 ± 0.00 min at 77, 80, 82 and 85 °C, respectively for RNase-treated SMV. Corresponding zD values were 3.80 °C and 3.71 °C for PMA and RNase-treated virus, respectively. Electron microscopy data applied to heat-treated virus-like particles supported this relatively high degree of thermal resistance. The data suggest that SMV is more heat resistant than common cultivable HuNoV surrogates. Standardized thermal inactivation methods (such as milk pasteurization) may not be stringent enough to eliminate this virus and perhaps other HuNoV.


Assuntos
Norovirus/química , Norovirus/isolamento & purificação , Inativação de Vírus , Azidas/química , Infecções por Caliciviridae/virologia , Temperatura Alta , Humanos , Norovirus/genética , Norovirus/fisiologia , Reação em Cadeia da Polimerase , Propídio/análogos & derivados , Propídio/química , RNA Viral/química , RNA Viral/genética
5.
Nat Cell Biol ; 3(2): 121-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11175743

RESUMO

Agonist-induced Ca2+ entry into cells by both store-operated channels and channels activated independently of Ca2+-store depletion has been described in various cell types. The molecular structures of these channels are unknown as is, in most cases, their impact on various cellular functions. Here we describe a store-operated Ca2+ current in vascular endothelium and show that endothelial cells of mice deficient in TRP4 (also known as CCE1) lack this current. As a consequence, agonist-induced Ca2+ entry and vasorelaxation is reduced markedly, showing that TRP4 is an indispensable component of store-operated channels in native endothelial cells and that these channels directly provide an Ca2+-entry pathway essentially contributing to the regulation of blood vessel tone.


Assuntos
Canais de Cálcio/fisiologia , Cálcio/metabolismo , Proteínas de Transporte de Cátions , Endotélio Vascular/metabolismo , Vasodilatação , Acetilcolina/farmacologia , Animais , Canais de Cálcio/genética , Quelantes/farmacologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Eletrofisiologia , Endotélio Vascular/citologia , Inibidores Enzimáticos/farmacologia , Feminino , Marcação de Genes , Hidroquinonas/farmacologia , Técnicas In Vitro , Inositol 1,4,5-Trifosfato/farmacologia , Lantânio/metabolismo , Masculino , Camundongos , Técnicas de Patch-Clamp , Canais de Cátion TRPC
6.
AJNR Am J Neuroradiol ; 42(7): 1231-1238, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33985952

RESUMO

BACKGROUND AND PURPOSE: The association of perivascular spaces in the centrum semiovale with amyloid accumulation among patients with Alzheimer disease-related cognitive impairment is unknown. We evaluated this association in patients with Alzheimer disease-related cognitive impairment and ß-amyloid deposition, assessed with [18F] florbetaben PET/CT. MATERIALS AND METHODS: MR imaging and [18F] florbetaben PET/CT images of 144 patients with Alzheimer disease-related cognitive impairment were retrospectively evaluated. MR imaging-visible perivascular spaces were rated on a 4-point visual scale: a score of ≥3 or <3 indicated a high or low degree of MR imaging-visible perivascular spaces, respectively. Amyloid deposition was evaluated using the brain ß-amyloid plaque load scoring system. RESULTS: Compared with patients negative for ß-amyloid, those positive for it were older and more likely to have lower cognitive function, a diagnosis of Alzheimer disease, white matter hyperintensity, the Apolipoprotein E ε4 allele, and a high degree of MR imaging-visible perivascular spaces in the centrum semiovale. Multivariable analysis, adjusted for age and Apolipoprotein E status, revealed that a high degree of MR imaging-visible perivascular spaces in the centrum semiovale was independently associated with ß-amyloid positivity (odds ratio, 2.307; 95% CI, 1.036-5.136; P = .041). CONCLUSIONS: A high degree of MR imaging-visible perivascular spaces in the centrum semiovale independently predicted ß-amyloid positivity in patients with Alzheimer disease-related cognitive impairment. Thus, MR imaging-visible perivascular spaces in the centrum semiovale are associated with amyloid pathology of the brain and could be an indirect imaging marker of amyloid burden in patients with Alzheimer disease-related cognitive impairment.


Assuntos
Doença de Alzheimer , Cérebro/diagnóstico por imagem , Disfunção Cognitiva , Sistema Glinfático/diagnóstico por imagem , Placa Amiloide/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Cérebro/patologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Sistema Glinfático/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Placa Amiloide/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Estudos Retrospectivos
7.
Br J Anaesth ; 105(2): 162-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20542888

RESUMO

BACKGROUND: Remifentanil is associated with increased incidence of post-anaesthetic shivering (PAS). The aim of this study was to compare the effects of intraoperative high and low doses of remifentanil on PAS. METHODS: We investigated 50 consecutive patients, aged <60 yr, who underwent gynaecological laparotomy. Patients who underwent prolonged surgery (>4 h) were excluded from the study. Anaesthesia throughout surgery was maintained with i.v. propofol and remifentanil, and epidural ropivacaine, and no nitrous oxide was used. Fifty patients were randomly assigned to receive intraoperative remifentanil at 0.1 microg kg(-1) min(-1) (low-dose group, n=25) or 0.25 microg kg(-1) min(-1) (high-dose group, n=25) until the end of surgery. Intraoperative analgesia was achieved by a fixed infusion rate of remifentanil and titrated epidural ropivacaine. PAS was evaluated by nursing stuff over the first hour after surgery. RESULTS: PAS occurred more frequently in the high-dose group than in the low-dose group (60% vs 20%, P=0.009). None of the patients complained of pain during the observation period due to epidural analgesia. There were no significant differences in rectal or palm skin temperature after extubation between the two dose groups. CONCLUSIONS: Remifentanil-induced PAS is not a phenomenon of intraoperative hypothermia. The higher incidence of PAS with higher doses of remifentanil probably reflects acute opioid tolerance and stimulation of N-methyl-d-aspartate receptors, similar to hyperalgesia. We conclude that patients administered high doses of remifentanil are sensitive to shivering after sudden drug withdrawal.


Assuntos
Anestésicos Intravenosos/administração & dosagem , Piperidinas/administração & dosagem , Complicações Pós-Operatórias , Estremecimento/efeitos dos fármacos , Adulto , Anestésicos Intravenosos/efeitos adversos , Anestésicos Intravenosos/farmacologia , Temperatura Corporal , Relação Dose-Resposta a Droga , Feminino , Doenças dos Genitais Femininos/cirurgia , Humanos , Período Intraoperatório , Pessoa de Meia-Idade , Piperidinas/efeitos adversos , Piperidinas/farmacologia , Remifentanil
8.
Int J Sports Med ; 30(10): 733-40, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19774501

RESUMO

The purpose of this study was to investigate the effects of fatness and fitness on insulin resistance (IR) and cardiovascular disease (CVD) risk factors among Korean adolescents. A total of 322 male high school students participated Departme nt of Sport and Leisure Studies, Yonsei University, Seoup, Republic of Korea Department of Sport and Leisure Studies, Yonsei University, Seoup, Republic of Korea in the cross-sectional part of the study. To determine the interaction of fatness and fitness levels on IR and CVD risk factors, subjects were stratified into four groups based on their body mass index (BMI) and cardio-respiratory fitness. Subjects who were in the high-fat category had significantly higher IR and CVD risk score than subjects in the low-fat category regardless of their fitness level. Subjects who were in high-fat-high-fit group showed significantly lower IR and CVD risk score than high-fat-low-fit group. Twenty-nine obese and unfit subjects participated in the intervention study. Twelve weeks of exercise training significantly reduced body weight (4.11+/-0.75 kg) and improved VO(2max) which resulted in a significant improvement in IR and CVD risk score (2.16+/-0.62 vs. 0.20+/-0.75). Interestingly, improvement in cardio-respiratory fitness and small reduction in body weight in relatively short-term significantly reduced the CVD risk score to the level of low-fat-low-fit subjects. Our results show the importance of fitness in determining IR and CVD risk factors among obese adolescents.


Assuntos
Doenças Cardiovasculares/epidemiologia , Resistência à Insulina/fisiologia , Obesidade/complicações , Aptidão Física/fisiologia , Povo Asiático , Glicemia/análise , Índice de Massa Corporal , Doenças Cardiovasculares/etnologia , Criança , Estudos Transversais , Humanos , Coreia (Geográfico)/epidemiologia , Lipídeos/sangue , Masculino , Obesidade/etnologia , Consumo de Oxigênio , Vigilância da População , Medição de Risco , Fatores de Risco
9.
Acta Neurochir (Wien) ; 150(5): 447-52; discussion 452, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18278572

RESUMO

BACKGROUND: Pre-operative embolisation is an effective method used to reduce intra-operative bleeding and operative difficulty in hypervascular brain tumour surgery. However, embolisation of the internal carotid artery (ICA) and pial tumour feeding branches has certain limitations. METHODS: From March 2000 to November 2006, 8 patients underwent superselective embolisation for hypervascular brain tumour. Seven tumours were extra-axial (6 meningiomas, 1 solitary fibrous tumour) and 1 was intra-axial (metastatic hepatocellular carcinoma). RESULTS: In all patients, feeding vessels from ICA branches or pial arteries were successfully embolised using superselective microcatheterisation. A provocative test was applied in 4 patients who had tumours adjacent to the motor cortex. Angiographic devascularisation was slight to extensive. Mean devascularisation on post-embolisation MRI ranged from 40 to 80% (mean 63.8%). One patient (12.5%) suffered an embolisation-related complication (loss of choroidal brush), but was not clinically worse because of the pre-existing blindness. CONCLUSIONS: Superselective embolisation of ICA branches or pial vessels should be performed if several conditions are met, especially angiographic findings, pre-existing neurologic deficits, provocative test, and technical feasibility. If the ICA embolisation for hypervascular tumour is successfully achieved, the bleeding loss and operative risk can be reduced.


Assuntos
Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/terapia , Artéria Carótida Interna , Embolização Terapêutica , Procedimentos Neurocirúrgicos , Pia-Máter/irrigação sanguínea , Cuidados Pré-Operatórios , Adulto , Perda Sanguínea Cirúrgica/prevenção & controle , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/secundário , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/secundário , Carcinoma Hepatocelular/terapia , Angiografia Cerebral , Embolização Terapêutica/efeitos adversos , Feminino , Humanos , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética , Masculino , Neoplasias Meníngeas/irrigação sanguínea , Neoplasias Meníngeas/terapia , Meningioma/irrigação sanguínea , Meningioma/terapia , Pessoa de Meia-Idade
10.
Acta Neurochir (Wien) ; 150(6): 557-61, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18458810

RESUMO

Indirect carotid-cavernous sinus dural arterio-venous fistulae (cDAVF) can be treated by transarterial and/or transvenous embolisation. This study evaluated patients with cDAVF who underwent transvenous embolisation using the direct superior ophthalmic vein (SOV) approach. Between January 2004 and October 2006, eight cDAVF in seven patients were embolised using direct surgical exposure of the SOV when access to the cDAVF via transarterial or transfemoral venous routes was not feasible. Medical records and imaging studies were retrospectively reviewed. The seven patients consisted of four females and three males from 43 to 65-year-old (mean age, 54.4 years). Six cDAVF lesions were located on the left side and two on the right. All fistulae were successfully embolised and showed clinical improvement. One patient presented after treatment with transient venous congestion on the brain stem, which was relieved by osmotic diuretics and steroids. Direct surgical exposure of the SOV for transvenous embolisation of cDAVF can be effective if the facial vein, inferior petrosal sinus, and internal jugular vein are thrombosed. This approach is easy, safe, and effective when performed by a multidisciplinary team.


Assuntos
Fístula Carótido-Cavernosa/terapia , Embolização Terapêutica/métodos , Adulto , Idoso , Fístula Carótido-Cavernosa/diagnóstico , Angiografia Cerebral , Olho/irrigação sanguínea , Feminino , Seguimentos , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X , Veias
11.
AJNR Am J Neuroradiol ; 39(2): 273-279, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29301782

RESUMO

BACKGROUND AND PURPOSE: Development of noninvasive imaging biomarkers indicating the histology and the gene mutation status of brain metastasis from lung cancer is important. We aimed to investigate diffusion-weighted imaging parameters as predictors of the histology and gene mutations of brain metastasis from lung cancer. MATERIALS AND METHODS: DWI data for 74 patients with brain metastasis from lung cancer were retrospectively reviewed. The patients were first grouped according to the primary tumor histology (adenocarcinoma, small-cell lung cancer, squamous cell carcinoma), and those with adenocarcinoma were further divided into epidermal growth factor receptor (EFGR) mutation-positive and wild type groups. Sex; age; number, size, and location of brain metastasis; DWI visual scores; the minimum ADC; and the normalized ADC ratio were compared among groups using χ2 and ANOVA. Multiple logistic regression analysis was performed to determine independent predictors of the EGFR mutation. RESULTS: The minimum ADC was lower in the small-cell lung cancer group than in the other 2 groups, though the difference was not significant. Furthermore, minimum ADC and the normalized ADC ratio were significantly lower in the EGFR mutation-positive group than in the wild type group (P = .021 and .014, respectively). Multivariate analysis revealed that minimum ADC and the normalized ADC ratio were independently associated with the EGFR mutation status (P = .028 and .021, respectively). CONCLUSIONS: Our results suggest that DWI parameters (minimum ADC and normalized ADC ratio) for the solid components of brain metastasis from lung cancer are not correlated with their histology, whereas they can predict the EGFR mutation status in brain metastasis from lung adenocarcinoma.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Idoso , Receptores ErbB/genética , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mutação , Estudos Retrospectivos
12.
AJNR Am J Neuroradiol ; 28(4): 709-13, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17416826

RESUMO

BACKGROUND AND PURPOSE: "Gossypiboma" is a term used to describe a mass within the body that comprises a cotton matrix surrounded by a foreign-body reaction, which is extremely rare after spinal surgery. The purpose of this study was to describe the clinical and MR imaging features of gossypibomas in the paravertebral area of 7 patients. MATERIALS AND METHODS: Between October 1999 and December 2005, 7 cases of paravertebral gossypibomas were confirmed pathologically at 2 institutions. The clinical features were reviewed retrospectively. We recorded MR imaging features and differential MR imaging-based diagnoses. RESULTS: All patients were symptomatic; the most frequent symptom was nonspecific back or neck pain. None of the patients presented with signs of infection or required surgery urgently. In 3 of the 7 patients, gossypiboma was included in the preoperative differential imaging diagnosis. In all patients, the gossypiboma was located in the vicinity of the initial site of surgery. Typically, gossypibomas were visible in T2-weighted images as a mass with a hyperintense center and hypointense rim and exhibited strong peripheral enhancement in contrast-enhanced images. Retained surgical gauze was removed surgically from 4 patients; in the remaining patients, the surgical specimens contained suture threads. CONCLUSION: Gossypiboma should be included in the differential diagnosis of the paravertebral mass when a mass with a hyperintense center and peripheral hypointense rim on T2-weighted images and strong peripheral rim enhancement on contrast-enhanced T1-weighted MR images is seen in postoperative patients.


Assuntos
Reação a Corpo Estranho/diagnóstico , Laminectomia , Imageamento por Ressonância Magnética , Tampões de Gaze Cirúrgicos , Suturas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Coluna Vertebral
13.
Bioelectrochemistry ; 71(2): 126-34, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17409027

RESUMO

Monitoring of the titanium, Ti-5Al-4V, Ti-6Al-4Fe implant materials--Ringer 1 and Ringer 2 solutions (of different pH values) interface for long term was studied in this work. In Ringer 1 solution (with high chloride ion content) all biomaterials present self-passivation. On Ti-6Al-4Fe alloy, the breakdown of the passive film was registered but at high pitting potential; pitting protection potential is very noble and can not be reached in human fluids. In Ringer 2 solution was obtained more electropositive corrosion potential values than in Ringer 1 solution; pitting corrosion of Ti-6Al-4Fe alloy is characterised by nobler breakdown and pitting protection potential values, therefore a better pitting corrosion resistance and tendency. Ion release increases in time, for the first 400-600 immersion hours and then tend to a constant level with very low values, non-dangerous for human body. All open circuit potentials oscillate around some electropositive values. The potential gradients calculated for extreme pH values have low values during 20,000 exposure hours and can not accelerate the corrosion. Atomic Force Microscopy images obtained after different exposure periods in Ringer 1 solution revealed that the roughness increased in time, suggesting a dynamic process at biomaterial-biofluid interface. X-ray Photoelectron spectra obtained after 2880 immersion hours in Ringer 2 solution show the existence of protective titanium dioxide TiO(2) and TiO and Ti(2)O(3) oxides both for titanium and Ti-5Al-4V alloy. Also, Al(2)O(3) oxide was detected.


Assuntos
Ligas/química , Materiais Biocompatíveis/química , Titânio/química , Corrosão , Eletroquímica , Humanos , Concentração de Íons de Hidrogênio , Soluções Isotônicas/química , Teste de Materiais , Microscopia de Força Atômica , Solução de Ringer , Espectrofotometria Atômica , Propriedades de Superfície , Fatores de Tempo
14.
AJNR Am J Neuroradiol ; 38(11): 2089-2093, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28882865

RESUMO

BACKGROUND AND PURPOSE: There is an uncertainty about the association between intracranial aneurysms and aortic dissection. We aimed to determine the prevalence of intracranial aneurysms in patients with aortic dissection and evaluate the independent risk factors for the presence of intracranial aneurysms in these patients. MATERIALS AND METHODS: Seventy-one patients with a confirmed aortic dissection who underwent additional brain imaging were enrolled as the aortic dissection group, and 2118 healthy individuals with brain imaging, as controls. Demographic data were obtained from their medical records, including age, sex, comorbidities, and arch vessel involvement of aortic dissection. Two readers reviewed all brain images independently regarding the presence, morphology, size, and location of intracranial aneurysms. Baseline characteristics were compared between the aortic dissection group and controls by propensity score matching, and logistic regression analysis was performed for independent risk factors for the presence of intracranial aneurysms. RESULTS: The prevalence of intracranial aneurysms was 12.96% in the aortic dissection group and 1.85% in controls (P = .022). The mean diameter of intracranial aneurysms was significantly larger in the aortic dissection group (5.79 ± 3.26 mm in aortic dissection versus 3.04 ± 1.57 mm in controls; P = .008), and intracranial aneurysms of >7 mm were also more common in the aortic dissection group (28.6% in aortic dissection versus 5.3% in controls, P = .003). On multivariate analysis, arch vessel involvement of aortic dissection was an independent risk factor for the presence of intracranial aneurysms (odds ratio, 6.246; 95% confidence interval, 1.472-26.50; P = .013). CONCLUSIONS: Patients with aortic dissection have a high prevalence of intracranial aneurysms, and selective screening for brain vessels could be considered in these patients with arch vessel involvement. A further prospective study is needed to demonstrate a substantial prevalence of intracranial aneurysms.


Assuntos
Dissecção Aórtica/complicações , Dissecção Aórtica/epidemiologia , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/epidemiologia , Adulto , Idoso , Dissecção Aórtica/diagnóstico por imagem , Aorta Torácica/diagnóstico por imagem , Angiografia Cerebral , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Aneurisma Intracraniano/diagnóstico por imagem , Estimativa de Kaplan-Meier , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Prevalência , Pontuação de Propensão , Estudos Prospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X
15.
Placenta ; 27(4-5): 438-44, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16009421

RESUMO

Nitric oxide is produced enzymatically by the nitric oxide synthase (NOS), which converts L-arginine in the presence of oxygen to L-citrulline and NO. Moreover, it has been reported that asymmetric dimethylarginine (ADMA) acts as is an endogenous inhibitor of endothelial NOS (eNOS) by competing with the enzyme for L-arginine. In this study, we measured L-arginine and ADMA in normal and preeclamptic women, and also investigated the association between the Glu298Asp eNOS gene polymorphism and preeclampsia. Finally, we assessed eNOS expression levels in the placentas of both normal and preeclamptic patients, using Western blot and immunohistochemistry. L-arginine levels were found to be significantly lower in the preeclamptic women than in the normal pregnant women (p=0.02) but there were no significant differences in ADMA levels between the normal and preeclamptic women. We also determined there to be no association between the Glu298Asp eNOS gene and preeclampsia. With regard to placental eNOS expression, we detected a lower degree of eNOS expression in the preeclamptic syncytiotrophoblasts than in the normal syncytiotrophoblasts. We suggest that reduced L-arginine levels, rather than increased ADMA levels, contribute to the development of preeclampsia, and also that decreased placental eNOS expression constitutes a characteristic finding in preeclamptic placentas.


Assuntos
Arginina/análogos & derivados , Arginina/sangue , Óxido Nítrico Sintase Tipo III/genética , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Adulto , Arginina/metabolismo , Western Blotting , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica , Óxido Nítrico Sintase Tipo III/metabolismo , Polimorfismo Genético , Pré-Eclâmpsia/genética , Gravidez , Estudos Retrospectivos
16.
AJNR Am J Neuroradiol ; 27(10): 2078-82, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17110671

RESUMO

BACKGROUND AND PURPOSE: To describe the results of transvenous embolizations of cavernous dural arteriovenous fistua (cDAVF) with an emphasis on identifying the incidence, characteristics, and management strategies associated with the complications of transvenous embolization of cDAVFs. METHODS: Fifty-six consecutive patients who were treated by transvenous embolization for cDAVFs were reviewed. The approach routes, angiographic results, complications, and clinical outcome were assessed. RESULTS: Retrograde inferior petrosal sinus (n = 36), transfacial vein (n = 7), transcontralateral intercavernous sinus (n = 4), and direct superior ophthalmic vein (n = 3) approaches were used. Angiographic results showed complete occlusion (n = 29), nearly complete occlusion (n = 13), and incomplete occlusion (n = 14). Complications associated with the procedures were cranial nerve palsy (n = 6), venous perforation (n = 3), and brain stem congestion (n = 2). The cranial nerve signs resolved with conservative treatment. Venous perforations were managed by coil embolizations at the site of the tear with no significant neurologic sequelae. One case of brain stem congestion resulted in hemiplegia after conservative treatment. The other case showed venous congestion as a result of rerouting of the shunted flow after venous embolization that was successfully managed by covered stent deployment for occlusion of the residual feeders. Clinical follow-up data were available in 46 patients. Complete resolution or improvement of symptoms was seen in 42 patients (91%). CONCLUSIONS: Cavernous DAVFs may be effectively treated by transvenous embolization. However, the procedure can be associated with various complications, some of which can potentially result in significant morbidity. Prompt diagnosis of the complications with appropriate management strategies is mandatory for a safe procedure.


Assuntos
Malformações Vasculares do Sistema Nervoso Central/terapia , Embolização Terapêutica/efeitos adversos , Embolização Terapêutica/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
17.
AJNR Am J Neuroradiol ; 27(4): 780-5, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16611764

RESUMO

BACKGROUND AND PURPOSE: The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and histopathologic analyses. METHOD: One-hour temporary occlusion of the left middle cerebral artery of cats was performed in the control ischemia group (n = 10), and 100 mg/kg of agmatine was intravenously injected immediately after recanalization in the agmatine-treated group (n = 15). MR imaging was performed at 1, 24, and 48 hours after recanalization, and the perfusion patterns were investigated. Terminal-deoxynucleotidyl transferase mediated nick and end-labeling (TUNEL) and hematoxylin-eosin (H&E) stainings were performed at the corresponding sections. RESULTS: In the control ischemia group, the number of TUNEL-positive cells was significantly increased in the areas with reperfusion hyperemia (P < .05). In the agmatine-treated group, no significant increase in the number of TUNEL-positive cells was noted in the areas of reperfusion hyperemia. The difference in the number of TUNEL-positive cells between the control ischemia and agmatine-treated group in the areas of reperfusion hyperemia was significant (P < .05). The total number of TUNEL-positive cells and the area of severe ischemic neuronal damage on H&E stain were also significantly attenuated in the agmatine-treated cats compared with the control ischemia cats (P < .05). CONCLUSION: Our results suggest that agmatine has neuroprotective effects against reperfusion injury and ischemia.


Assuntos
Agmatina/uso terapêutico , Ataque Isquêmico Transitório/tratamento farmacológico , Ataque Isquêmico Transitório/patologia , Imageamento por Ressonância Magnética , Animais , Gatos , Circulação Cerebrovascular , Modelos Animais de Doenças , Ataque Isquêmico Transitório/fisiopatologia , Fatores de Tempo
18.
AJNR Am J Neuroradiol ; 37(2): 285-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26381554

RESUMO

BACKGROUND AND PURPOSE: Although various revascularization scales are used in the angiographic evaluation of acute ischemic stroke, observer reliability tests of these scales have been rarely performed for posterior circulation stroke. We aimed to evaluate inter- and intraobserver variability of 2 scales, the modified Treatment in Cerebral Ischemia and the Arterial Occlusive Lesion, in posterior circulation stroke. MATERIALS AND METHODS: Three independent readers interpreted pre- and postthrombolytic angiographies of 62 patients with posterior circulation stroke by using the modified Treatment in Cerebral Ischemia and Arterial Occlusive Lesion scales. The κ statistic was used to measure observer agreement for both scales, and κ > 0.6 was considered substantial agreement. RESULTS: For the Arterial Occlusive Lesion scale, inter- and intraobserver agreement was >0.6. While intraobserver agreement of the modified Treatment in Cerebral Ischemia scale was >0.6 except for 1 reader, interobserver agreement was lower in dichotomized and original scales. In 49 cases with solely basilar artery occlusion, inter- and intraobserver agreement of both scales was similar to that in all 62 patients with posterior circulation stroke. In 2 consecutive readings, there was a significant decrease in the proportion of mTICI 2a reads (22.58% in the first versus 13.44% in the second session, P < .03) and a reciprocal increase in the sum of proportions for modified Treatment in Cerebral Ischemia 2b and modified Treatment in Cerebral Ischemia 3 reads (62.37% in the first versus 72.58% in the second session, P < .046). CONCLUSIONS: In angiographic assessment of posterior circulation stroke, inter- and intraobserver agreement for the Arterial Occlusive Lesion scale was reliable, while the modified Treatment in Cerebral Ischemia failed to achieve substantial interobserver agreement. The clinical impact of this result needs to be validated in future studies.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Revascularização Cerebral , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/terapia , Angiografia Cerebral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/terapia , Terapia Trombolítica
19.
AJNR Am J Neuroradiol ; 36(2): 337-41, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25324496

RESUMO

BACKGROUND AND PURPOSE: Skull plain films of coiled aneurysms have been used in a limited role, including morphologic comparison of the coil mass. We aimed to evaluate the efficacy of skull plain films in patients treated with detachable coils by using quantitative assessment. MATERIALS AND METHODS: In this retrospective study, 78 pairs of the initial and follow-up skull anteroposterior and lateral images were reviewed independently by 2 neuroradiologists. The largest diameter, the perpendicular diameter, and area of the coil mass were measured separately on plain film, and quantitative changes of parameters were compared between subgroups, which were determined by consensus, depending on the need for retreatment. Subgroup analysis was also performed according to aneurysm size, packing attenuation, and ruptured status. RESULTS: On skull lateral images, mean quantitative changes of the largest diameter (0.53 ± 0.43 mm versus 1.17 ± 0.91 mm, P < .01), the perpendicular diameter (0.56 ± 0.48 mm versus 1.20 ± 1.05 mm, P < .01), and the area of the coil mass (5.21 ± 7.51 mm(2) versus 10.55 ± 10.93 mm(2), P < .02) differed significantly between subgroups. Receiver operating characteristic analysis showed quantitative change of the largest diameter (>1.1 mm; sensitivity, 50.0%; specificity, 90.3%), the perpendicular diameter (>.9 mm; sensitivity, 62.5%; specificity, 85.5%), and the area (>8.5 mm(2); sensitivity, 50.0%; specificity, 83.9%) on skull lateral films to be indicative of aneurysm recurrence, and the diagnostic accuracy of these parameters increased significantly in the high-packing-attenuation group. CONCLUSIONS: Quantitative measurement of the coil mass by using skull plain lateral images has the potential to predict aneurysm recurrence in follow-up evaluations of intracranial aneurysms with coiling.


Assuntos
Embolização Terapêutica/instrumentação , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Crânio/diagnóstico por imagem , Adulto , Idoso , Área Sob a Curva , Angiografia Cerebral/instrumentação , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Recidiva , Estudos Retrospectivos , Sensibilidade e Especificidade
20.
AJNR Am J Neuroradiol ; 36(11): 2042-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26228881

RESUMO

BACKGROUND AND PURPOSE: Fluid-attenuated inversion recovery hyperintense vessels in stroke represent leptomeningeal collateral flow. We presumed that FLAIR hyperintense vessels would be more closely associated with arterial stenosis and perfusion abnormality in ischemic stroke on T2-PROPELLER-FLAIR than on T2-FLAIR. MATERIALS AND METHODS: We retrospectively reviewed 35 patients with middle cerebral territorial infarction who underwent MR imaging. FLAIR hyperintense vessel scores were graded according to the number of segments with FLAIR hyperintense vessels in the MCA ASPECTS areas. We compared the predictability of FLAIR hyperintense vessels between T2-PROPELLER-FLAIR and T2-FLAIR for large-artery stenosis. The interagreement between perfusion abnormality and FLAIR hyperintense vessels was assessed. In subgroup analysis (9 patients with MCA horizontal segment occlusion), the association of FLAIR hyperintense vessels with ischemic lesion volume and perfusion abnormality volume was evaluated. RESULTS: FLAIR hyperintense vessel scores were significantly higher on T2-PROPELLER-FLAIR than on T2-FLAIR (3.50 ± 2.79 versus 1.21 ± 1.47, P < .01), and the sensitivity for large-artery stenosis was significantly improved on T2-PROPELLER-FLAIR (93% versus 68%, P = .03). FLAIR hyperintense vessels on T2-PROPELLER-FLAIR were more closely associated with perfusion abnormalities than they were on T2-FLAIR (κ = 0.64 and κ = 0.27, respectively). In subgroup analysis, FLAIR hyperintense vessels were positively correlated with ischemic lesion volume on T2-FLAIR, while the mismatch of FLAIR hyperintense vessels between the 2 sequences was negatively correlated with ischemic lesion volume (P = .01). CONCLUSIONS: In MCA stroke, FLAIR hyperintense vessels were more prominent on T2-PROPELLER-FLAIR compared with T2-FLAIR. In addition, FLAIR hyperintense vessels on T2-PROPELLER-FLAIR have a significantly higher sensitivity for predicting large-artery stenosis than they do on T2-FLAIR. Moreover, the areas showing FLAIR hyperintense vessels on T2-PROPELLER-FLAIR were more closely associated with perfusion abnormality than those on T2-FLAIR.


Assuntos
Infarto da Artéria Cerebral Média/patologia , Imageamento por Ressonância Magnética/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Perfusão , Estudos Retrospectivos
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